|
|
|
/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
|
|
|
|
It is considered beerware. Prost. Skol. Cheers or whatever.
|
|
|
|
|
|
|
|
$id$ */
|
|
|
|
|
|
|
|
/* System */
|
|
|
|
#include <string.h>
|
|
|
|
#include <arpa/inet.h>
|
|
|
|
#include <stdio.h>
|
|
|
|
|
|
|
|
/* Libowfat */
|
|
|
|
#include "socket.h"
|
|
|
|
#include "io.h"
|
|
|
|
|
|
|
|
/* Opentracker */
|
|
|
|
#include "trackerlogic.h"
|
|
|
|
#include "ot_udp.h"
|
|
|
|
#include "ot_stats.h"
|
|
|
|
|
|
|
|
static const uint8_t g_static_connid[8] = { 0x23, 0x42, 0x05, 0x17, 0xde, 0x41, 0x50, 0xff };
|
|
|
|
|
|
|
|
static void udp_make_connectionid( uint32_t * connid, const ot_ip6 remoteip ) {
|
|
|
|
/* Touch unused variable */
|
|
|
|
(void)remoteip;
|
|
|
|
|
|
|
|
/* Use a static secret for now */
|
|
|
|
memcpy( connid, g_static_connid, 8 );
|
|
|
|
}
|
|
|
|
|
|
|
|
/* UDP implementation according to http://xbtt.sourceforge.net/udp_tracker_protocol.html */
|
|
|
|
void handle_udp6( int64 serversocket, struct ot_workstruct *ws ) {
|
|
|
|
ot_ip6 remoteip;
|
|
|
|
uint32_t *inpacket = (uint32_t*)ws->inbuf;
|
|
|
|
uint32_t *outpacket = (uint32_t*)ws->outbuf;
|
|
|
|
uint32_t numwant, left, event, scopeid;
|
|
|
|
uint16_t port, remoteport;
|
|
|
|
size_t byte_count, scrape_count;
|
|
|
|
|
|
|
|
byte_count = socket_recv6( serversocket, ws->inbuf, G_INBUF_SIZE, remoteip, &remoteport, &scopeid );
|
|
|
|
|
|
|
|
stats_issue_event( EVENT_ACCEPT, FLAG_UDP, (uintptr_t)remoteip );
|
|
|
|
stats_issue_event( EVENT_READ, FLAG_UDP, byte_count );
|
|
|
|
|
|
|
|
/* Initialise hash pointer */
|
|
|
|
ws->hash = NULL;
|
|
|
|
ws->peer_id = NULL;
|
|
|
|
|
|
|
|
/* Minimum udp tracker packet size, also catches error */
|
|
|
|
if( byte_count < 16 )
|
|
|
|
return;
|
|
|
|
|
|
|
|
switch( ntohl( inpacket[2] ) ) {
|
|
|
|
case 0: /* This is a connect action */
|
|
|
|
/* look for udp bittorrent magic id */
|
|
|
|
if( (ntohl(inpacket[0]) != 0x00000417) || (ntohl(inpacket[1]) != 0x27101980) )
|
|
|
|
return;
|
|
|
|
|
|
|
|
outpacket[0] = 0;
|
|
|
|
outpacket[1] = inpacket[3];
|
|
|
|
udp_make_connectionid( outpacket + 2, remoteip );
|
|
|
|
|
|
|
|
socket_send6( serversocket, ws->outbuf, 16, remoteip, remoteport, 0 );
|
|
|
|
stats_issue_event( EVENT_CONNECT, FLAG_UDP, 16 );
|
|
|
|
break;
|
|
|
|
case 1: /* This is an announce action */
|
|
|
|
/* Minimum udp announce packet size */
|
|
|
|
if( byte_count < 98 )
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* We do only want to know, if it is zero */
|
|
|
|
left = inpacket[64/4] | inpacket[68/4];
|
|
|
|
|
|
|
|
numwant = ntohl( inpacket[92/4] );
|
|
|
|
if (numwant > 200) numwant = 200;
|
|
|
|
|
|
|
|
event = ntohl( inpacket[80/4] );
|
|
|
|
port = *(uint16_t*)( ((char*)inpacket) + 96 );
|
|
|
|
ws->hash = (ot_hash*)( ((char*)inpacket) + 16 );
|
|
|
|
|
|
|
|
OT_SETIP( &ws->peer, remoteip );
|
|
|
|
OT_SETPORT( &ws->peer, &port );
|
|
|
|
OT_PEERFLAG( &ws->peer ) = 0;
|
|
|
|
|
|
|
|
switch( event ) {
|
|
|
|
case 1: OT_PEERFLAG( &ws->peer ) |= PEER_FLAG_COMPLETED; break;
|
|
|
|
case 3: OT_PEERFLAG( &ws->peer ) |= PEER_FLAG_STOPPED; break;
|
|
|
|
default: break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if( !left )
|
|
|
|
OT_PEERFLAG( &ws->peer ) |= PEER_FLAG_SEEDING;
|
|
|
|
|
|
|
|
outpacket[0] = htonl( 1 ); /* announce action */
|
|
|
|
outpacket[1] = inpacket[12/4];
|
|
|
|
|
|
|
|
if( OT_PEERFLAG( &ws->peer ) & PEER_FLAG_STOPPED ) { /* Peer is gone. */
|
|
|
|
ws->reply = ws->outbuf;
|
|
|
|
ws->reply_size = remove_peer_from_torrent( FLAG_UDP, ws );
|
|
|
|
} else {
|
|
|
|
ws->reply = ws->outbuf + 8;
|
|
|
|
ws->reply_size = 8 + add_peer_to_torrent_and_return_peers( FLAG_UDP, ws, numwant );
|
|
|
|
}
|
|
|
|
|
|
|
|
socket_send6( serversocket, ws->outbuf, ws->reply_size, remoteip, remoteport, 0 );
|
|
|
|
stats_issue_event( EVENT_ANNOUNCE, FLAG_UDP, ws->reply_size );
|
|
|
|
break;
|
|
|
|
|
|
|
|
case 2: /* This is a scrape action */
|
|
|
|
outpacket[0] = htonl( 2 ); /* scrape action */
|
|
|
|
outpacket[1] = inpacket[12/4];
|
|
|
|
|
|
|
|
for( scrape_count = 0; ( scrape_count * 20 < byte_count - 16) && ( scrape_count <= 74 ); scrape_count++ )
|
|
|
|
return_udp_scrape_for_torrent( *(ot_hash*)( ((char*)inpacket) + 16 + 20 * scrape_count ), ((char*)outpacket) + 8 + 12 * scrape_count );
|
|
|
|
|
|
|
|
socket_send6( serversocket, ws->outbuf, 8 + 12 * scrape_count, remoteip, remoteport, 0 );
|
|
|
|
stats_issue_event( EVENT_SCRAPE, FLAG_UDP, scrape_count );
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
void udp_init( ) {
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
const char *g_version_udp_c = "$Source$: $Revision$\n";
|